Verbseoul.
ㅎ irregular (adj)
발갛다balgatdared

To say red politely in the present tense, use 발개요 (bahl-gae-yoh). Below is the full conjugation of 발갛다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
발개
bahl-gae
발개요
bahl-gae-yoh
발갛습니다
bahl-gah-sseum-nee-dah
Past
발갰어
bahl-gae-ssuh
발갰어요
bahl-gae-ssuh-yoh
발갰습니다
bahl-gae-sseum-nee-dah
Future
발갈 거야
bahl-gahl- -guh-yah
발갈 거예요
bahl-gahl- -guh-yae-yoh
발갈 겁니다
bahl-gahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
발가세요
bahl-gah-sae-yoh
Suggestion / Let's Polite (요)
발개요
bahl-gae-yoh
Question Polite (요)
발개요?
bahl-gae-yoh-?
Connective “and” — (고)
발갛고
bahl-gah-koh
Conditional “if” — (면)
발가면
bahl-gah-myuhn
Noun form — (기)
발감
bahl-gahm